Patients with major depressive disorder (MDD) are at increased risk of developing an autoimmune skin disease (ASD), according to a study published in the Journal of Affective Disorders.
MDD affects more than 10% of the US population and is associated with a high degree of disability. There may be a risk for depression among patients with ASDs but this relationship could be bidirectional. Animal models have indicated that psychological stress, a trigger for MDD, can lead to immune system dysregulation.
Ying-Xiu Dai, MD, of the Department of Dermatology, Taipei Veterans General Hospital, School of Medicine, National Yang-Ming University, Taipei, Taiwan, and colleagues recruited participants from the National Health Insurance Research Database to evaluate the risk of developing ASDs. They included 222,522 patients with MDD and 890,088 matched controls in the study sample. The primary outcome was new onset ASD based on several diagnostic codes.
The investigators found an increased risk of ASDs among patients with MDD (adjusted hazard ratio [aHR], 10.41; 95% CI, 9.62-11.42) compared to matched controls. Subgroup analyses showed significantly increased risk for a number of ASDs, including psoriasis (aHR, 12.01; 95% CI, 10.37-13.91), lichen planus (aHR, 11.84; 95% CI, 8.90-15.75), alopecia areata (aHR, 11.61; 95% CI, 9.92-13.59), morphea (aHR, 6.03; 95% CI, 2.47-14.73), autoimmune bullous disease (aHR, 7.67; 95% CI, 5.94-9.90), hidradenitis suppurativa. (aHR, 8.45; 95% CI, 3.61-19.74), vitiligo (aHR, 7.24; 95% CI, 5.65-9.28), lupus erythematosus (aHR, 11.30; 95% CI, 9.21-13.86), systemic sclerosis (aHR, 8.07; 95% CI, 4.30-15.14), Sjogren syndrome (aHR, 6.71; 95% CI, 5.29-8.50), and dermatomyositis (aHR, 14.44; 95% CI, 5.55-37.55), all independent of sex and age.
T-regulatory cells (Tregs) are a population of immune cells that maintain immune system equilibrium and inhibit proinflammatory cell responses. The researchers noted that Treg insufficiency may be a factor in the pathogenesis of MDD and such an insufficiency may create a proinflammatory state. This phenomenon may help explain some of the association between MDD and ASDs.
Study limitations included the use of a database that lacked some confounding factors, such as marital status, body mass index, history of smoking, and alcohol consumption, as well as no data concerning histopathological confirmation of ASD diagnosis.
“The ﬁndings of this study were consistent with the biological evidence linking MDD to varying impairments of immune function, which lend support to a biopsychosocial model in the etiology of autoimmune disease,” the researchers concluded.
Dai Y-X, Tai Y-H, Chang Y-T, Chen T-J, Chen M-H. Association between major depressive disorder and subsequent autoimmune skin diseases: A nationwide population-based cohort study. J Affect Disord. 2020;274:334-338.